1. Field of the Invention
The present invention relates in general to welding processes for aluminum workpieces and in particular to a method of arc welding aluminum driveshaft components together utilizing inert gas shielding.
In the field of welding aluminum and aluminum alloys, the practice of inert gas shielded arc welding is common. Such welding typically includes the use of either a consumable or non-consumable welding electrode and is customarily either automatic or semi-automatic in operation. Although not limited thereto, the present invention has particular application in welding practices which utilize a consumable electrode, wherein a filler wire constituting a consumable electrode is fed automatically to a welding gun. Upon actuation of the gun trigger, the filler wire is fed to a welding arc within an envelope of shielding inert gas, such as argon, helium, or mixtures thereof. The gun is moved such that the point of the wire electrode follows the seam to be welded.
The use of aluminum and aluminum alloys in automobiles is becoming increasingly popular. Such popularity is mainly due to the fact that aluminum components can be manufactured much lighter in weight than the comparable steel components which they replace without sacrificing strength or durability. For example, aluminum driveshaft components typically weigh up to one-third less than conventional steel driveshaft components. Also, aluminum components are less subject to failure from corrosion and the like. However, it is difficult to securely join such aluminum driveshaft components utilizing conventional welding practices.
2. Description of the Prior Art
U.S. Pat. No. 1,291,388 to Bright et al. discloses an improved shaft joint and a method of forming such a joint. A shaft stub is formed with an annular beveled shoulder and several longitudinal grooves, the shoulder being disposed at the inner end of the grooves. A tubular shaft is sleeved upon the shaft stub and swaged into the grooves to provide internal groove-engaging keys. To further reinforce and secure the joint, the end of the tubular shaft is welded upon the beveled shoulder of the shaft stub.
U.S. Pat. No. 3,791,026 to Dufrene et al. discloses a method of joining a niobium tube to a stainless steel tube. The method consists of fitting the end portion of the niobium tube within the end portion of the steel tube while maintaining a predetermined radial and annular clearance therebetween. The steel tube is provided at its extremity with an external machined flange so as to form a reservoir. The reservoir is filled with a suitable brazing compound, placed in a vacuum, and heated to a high temperature. When the brazing compound has penetrated into the clearance, the treatment is stopped and the flange is removed, together with any excess brazing material.
U.S. Pat. No. 3,078,818 to Butler discloses a method of compensating for the effect of cambered strip stock in making a helical seam metal tube. The strip is advanced longitudinally and formed into a helix, wherein the edges are welded together progressively to form a helical seam. The rear marginal edge portion of the strip is provided with a sloping shoulder and a flat terminal marginal section therebeyond. As the strip is longitudinally advanced to the partially completed tube, the helix angle thereof is adjusted as required by the camber of the strip to cause the near edge of the strip to engage the sloping shoulder at a given meeting point.
U.S. Pat. No. 2,852,659 to Belz et al. and U.S. Pat. No. 3,059,093 to Norcross et al. both disclose welding processes and electrodes for aluminum or aluminum alloy materials wherein an inert gas is utilized to shield the region of the weld from the atmosphere. A related welding process disclosed in U.S. Pat. No. 2,291,420 to Swenson.